Fig 1.
Shapefile reprinted from GADM database under a CC BY license, with permission from Global Administrative Areas (www.gadm.org). The figure was made with ArcGIS 10.3 under a CC BY license, with permission from ESRI (www.esri.com).
Fig 2.
Hanoi mapped by changes in built-up areas over time across the 5 km buffers from the city center.
Shapefile reprinted from GADM database under a CC BY license, with permission from Global Administrative Areas (www.gadm.org). The figure was made with ArcGIS 10.3 under a CC BY license, with permission from ESRI (www.esri.com).
Table 1.
Patch metrics selected for spatiotemporal analysis.
Fig 3.
Hypothetical sequence of the spatial evolution of an urban area.
Fig 4.
(a) Infilling growth which occurs within urbanized open space and increases contiguity of built-up area by filling in that space; (b) Edge expansion which refers to non-infill development intersecting the urban footprint and extending outward from previous development; and, (c) Spontaneous growth which neither intersects the urban footprint nor is contiguous with previously developed areas and has greatest effect on fragmentation of open lands.
Fig 5.
Annual growth rates of built-up area across different buffer zones.
Fig 6.
Percentages of infilling, edge expansion, and spontaneous growth areas and their percentage number of patches in the three time periods for Hanoi City.
Fig 7.
Percentages of infilling, edge expansion and spontaneous growth areas and their percentage number of patches in three time periods for twelve buffer zones.
Fig 8.
Spatial and temporal profiles of the area-weighted mean expansion index for twelve buffer zones.
Fig 9.
Mean selected patch metrics showing general landscape patterns over three time periods and across different buffer zones.
(a) Patch Density; (b) Edge Density; (c) Landscape Shape Index; (d) Largest Patch Index; (e) Area-weighted Mean Euclidean Nearest-Neighbor Distance; (f) Area-weighted Mean Patch Fractal Dimension.
Fig 10.
Changes in mean values of the patch metrics at different buffer zones over three time periods.
The changes in each patch metric across the three time periods was computed as the Difference in spatial metric i = Spatial metric i (t2)–Spatial metric i (t1). For a given patch metric, an increase in its value from time one (t1) to time two (t2) leads to a positive difference and a decrease in its value from t1 to t2 results in a negative difference.